Thermocouple Attachment for a Useful Reflow Profile Every reflow profile is only as good as the contact between the sensor and the surface it is meant to represent. A thermocouple attachment method that adds thermal mass, or that leaves an air gap beneath the bead, produces a curve that belongs…

Pin-in-Paste Printing: Getting Volume into Through Holes Pin-in-paste printing places solder paste into the through holes of a mixed-technology board so that the through-hole joints are formed in the same reflow cycle as the surface mount joints. The wave soldering step and the masking that goes with it both disappear,…

Stencil Life Management: Tension, Wear and Retire Criteria A stencil is a consumable that is treated like a fixture, and the difference between those two views costs money in both directions. A stencil retired too early wastes the tooling budget and the time taken to qualify a replacement, while one…

ICT Fixture Wiring: Keeping Resistance and Crosstalk in Check An in-circuit test measures small quantities: a few milliohms on a power path, a few picofarads between two nets, a few microvolts of leakage. The probe is usually blamed first when a measurement drifts, and in a well-built ICT fixture the…

HASL or ENIG: Selecting a Surface Finish for Assembly A surface finish exists to keep the copper of a pad solderable from the end of fabrication to the moment of assembly, and each finish does that in a different way and for a different length of time. HASL leaves a…

Solder Balling and the Reflow Profile: Why Balls Form Small spheres of alloy that remain on the board after reflow are known as solder balling, and it is one of the few assembly defects that a reflow profile can create on its own. The balls form when solder paste or…

PCB Impedance Coupon Records: Writing It Down Buyers and engineers often focus on the finished product and forget the production line behind it. In practice, most field failures can be traced back to process decisions made during assembly. Understanding PCB impedance coupon records gives you a practical advantage when you…

PCB Impedance Coupon Audit: Checking the Practice Electronics manufacturing has become a discipline of small details. Solder paste volumes, placement accuracy, temperature profiles and inspection limits all add up to the final result. This guide looks at PCB impedance coupon audit from the perspective of a PCBA factory floor, covering…

PCB Impedance Coupon Cost: What It Adds Up To Buyers and engineers often focus on the finished product and forget the production line behind it. In practice, most field failures can be traced back to process decisions made during assembly. Understanding PCB impedance coupon cost gives you a practical advantage…

PCB Impedance Coupon Standards: Agreeing the Rules Electronics manufacturing has become a discipline of small details. Solder paste volumes, placement accuracy, temperature profiles and inspection limits all add up to the final result. This guide looks at PCB impedance coupon standards from the perspective of a PCBA factory floor, covering…